The present invention relates to a metal-halogen secondary battery system in which the electrolyte circulating lines of positive and negative plate galvanic reaction chambers incorporate cleaning lines for cleaning the reaction chambers.
Secondary batteries known in the art are constructed so that in the case of the lead storage battery, for example, both the positive and negative plates are immersed in the same electrolyte contained in a battery case in which the plates are enclosed and the electrolyte is held in a stationary state, and the battery case is constructed by completely attaching the cover to the lower container, thus making it impossible from the structural point of view to take necessary measures for circulating the electrolyte, removing the cover to clean the interior of the battery case, etc. As a result, with the known secondary batteries it has been the usual practice to replace with new ones the inner components such as the plates when they are fouled with the products of electrolysis or the like and the electromotive force is decreased, thus inevitably causing an increase in the maintenance cost. Also, in the case of the metal-halogen secondary battery, in view of the nature of the battery that the active material on the halogen side (the positive plates) dissolves into the electrolyte, it is necessary to circulate the electrolyte so as to cause the active material to always contact uniformly with the plates and also the circulation of the electrolyte is effected as a means of preventing the precipitation of metal or the precipitation of a dendrite caused on the metal side (the negative plates) during the charging with a high current density. The electrolytes for the positive and negative plates are separated from each other by an ion exchange membrane so as to prevent the plate electrolytes from being mixed together and prevent the occurrence of self-discharge.